Humans ; Mycoplasma pneumoniae ; pathogenicity ; Pneumonia, Mycoplasma ; microbiology

Humans ; Mycoplasma pneumoniae ; Pneumonia, Mycoplasma ; microbiology

OBJECTIVETo reveal changes in clinical manifestations of Mycoplasma pneumoniae (Mp) pneumonia in children older than 3 years of age during 2000 - 2006.

METHODTotally 288 older children with Mp pneumonia hospitalized in the hospital between 2000 and 2006 were enrolled. Clinical manifestation, chest X-ray and clinical outcomes among three time periods (2000 - 2002, 2003 - 2004, 2005 - 2006) were compared.

RESULT(1) Fever and its duration; 281 cases (97.6%) had fever of different duration (median = 7.2 d, 8.5 d, and 11.2 d, respectively) among the time periods, showing statistically significant difference (P < 0.01). (2) Respiratory symptoms: different incidence of wheezing/dyspnea (6.1%, 9.9%, 16.3%), thrilling (6.9%, 11.3%, 19.8%) and chest pain (12.2%, 15.5%, 22.1%) among different time periods had significant difference (χ(2) = 5.87, 11.46, 5.21, P < 0.05). (3) The incidence of extrapulmonary damages (13.0%, 38.0%, 48.8%) among different time periods also had significant difference (χ(2) = 21.27, P < 0.01). (4) Chest X-ray examination showed large area of lesions in most cases; 30.2% of cases seen during 2005 - 2006 were found having pulmonary complications such as pleural effusion or atelectasis. The incidences of pulmonary complications among different time periods had significant difference (P < 0.01). (5) TREATMENT AND OUTCOME: after comparing the efficacy of erythromycin or azithromycin, decline of clinical effectiveness was revealed among different time periods (P < 0.05). The duration of fever after macrolide administration (median = 3.2 d, 4.5 d, 6.2 d, respectively) and hospital stay (median = 7.0 d, 8.7 d, and 11.4 d, respectively) among different time periods showed significant differences (P < 0.05).

CONCLUSIONMore refractory and severe Mp pneumonia cases appeared during 2000 - 2006 in children older than 3 years of age in Hangzhou, with prolonged fever duration, aggravated respiratory symptoms and more complications and extrapulmonary damages.

Adolescent ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Male ; Mycoplasma pneumoniae ; Pneumonia, Mycoplasma ; epidemiology ; microbiology

OBJECTIVETo study the clinical features and diagnostic methods of mycoplasma pneumonia complicated with cerebral infarction.

METHODData of 3 children with mycoplasma pneumonia who developed cerebral infarction, including clinical manifestations and imaging were collected, analyzed and the literature was reviewed.

RESULTAll the cases were pre-school or school-aged children, who developed the respiratory infection initially, the neurological symptoms were acute hemiparesis, with or without convulsion. The IgM antibody to Mycoplasma pneumoniae (Mp) was positive. Pulmonary imaging showed unilateral consolidation with atelectasis and pleural exudate. Neuroimaging showed occlusion of middle cerebral artery and infarction of its territory. After giving azithromycin, anti-coagulative and thrombolytic treatments, the neurological deficits recovered to some extent.

CONCLUSIONMycoplasma pneumonia were diagnosed based on respiratory symptoms and pulmonary imaging, the accompanied cerebral infarction was confirmed by neurological and neuroimaging findings.

Cerebral Infarction ; complications ; microbiology ; Child ; Child, Preschool ; Female ; Humans ; Male ; Mycoplasma pneumoniae ; Pneumonia, Mycoplasma ; complications

OBJECTIVEThe P1 protein of Mycoplasma pneumoniae (MP) plays an important role in the pathogenesis of MP pneumonia. It mediates the attachment of the pathogen to host cells and elicits a strong humoral immune response during infection. In early studies, only two types of MP P1 genes were assumed to exist. Later, eight subtypes of MP P1 genes and some variations of P1 gene were reported. However, there are no related reports in China until now. This study aimed to understand epidemiology of MP subtype in Zhejiang province, China, as well as the relationship between MP subtype and clinical severity of MP pneumonia.

METHODClinical samples were collected by nasopharyngeal aspiration from children with MP pneumonia hospitalized in the Children's Hospital of Zhejiang University School of Medicine from February to December in 2009. P1 gene fragment was amplified by using PCR method (with primers of ADH1/ADH2 and ADH3/ADH4, respectively). Then ADH1/ADH2-generated fragments were digested with HaeIII, HpaII, Sau3A, and the ADH3/ADH4-generated fragments digested with HaeIII, Sau3A, HhaI, RsaI. The MP P1 subtypes were determined based on resulting fragments. Part of samples were selected for sequencing. The clinical data of different MP subtype pneumonia were compared.

RESULTA total of 300 hospitalized children with MP pneumonia were enrolled in this study. All the samples produced specific bands for MP P1 gene after PCR with primers of ADH1/ADH2 and ADH3/ADH4 respectively. By restrictive fragment length polymorphism analysis, 297 clinical specimens showed the characteristic band patterns for P1 type 1 identical to Mp129, and only 3 clinical specimens showed the characteristic band pattern for P1 type 2 identical to MP-FH. All P1 type 1 and P1 type 2 showed the same subtype bands respectively, as subtype 1b and 2a. After sequencing, one synonymous point mutation in P1 type 1 was identified relative to the MP129 P1 sequence at nucleotide position (nt) 208(G→A). Three cases with P1 type 2 MP pneumonia were found to have liver damage, and longer hospital stay and fever duration than P1 type 1, but no statistically significant difference was found.

CONCLUSIONClinical samples can be used directly for genotyping of MP. The dominating type of MP in Zhejiang Province was P1 type 1 subtype 1b. But whether there was any relationship between MP subtype and clinical severity remains to be clarified.

Adhesins, Bacterial ; genetics ; Child ; China ; DNA, Bacterial ; genetics ; Genotype ; Humans ; Mycoplasma pneumoniae ; genetics ; isolation & purification ; Nasopharynx ; microbiology ; Pneumonia, Mycoplasma ; microbiology ; Polymorphism, Restriction Fragment Length

OBJECTIVETo summarize the epidemiology and clinical characteristics of Mycoplasma pneumoniae (MP) infection in children with acute respiratory tract infection (ARI) in Guangzhou.

METHODSMP was detected using an indirect immunofluorescent method in 2084 children with ARI. The relations between MP infection rate and the gender, age, season, site of infection and wheezing diseases were analyzed.

RESULTSA total of 433 children (20.8%) were positive for MP, including 222 boys (19.8%) and 211 girls (21.9%) without significant difference in the infection rate between the genders (P>0.05). In 0- to 3-year-old group, 106 children were positive for MP (15.0%), while in 3- to 5-year-old group and 5- to 14-year-old group, 163 (25.2%) and 164 (22.5%) were positive, respectively, showing a significant difference in the infection rate between the 3 groups (P<0.05). The MP infection rate was 18.0% in January to March, 25.1% in April to June, 17.7% in July to September, and 20.5% in October to December, showing significant differences between the periods (P<0.05). No significant difference was found in the infection rate between children with acute upper respiratory tract infection (URI) and those with lower respiratory tract infection (LRI) (P>0.05). Among the children with LRI, those having wheezing disease had significantly higher MP positivity rate than those without wheezing.

CONCLUSIONMP is a common causative agent for ARI in children. MP infection is not related to gender and infection site, but to age and season. Children over 3 years old are vulnerable to MP infection. MP infection can be associated with wheezing in LRI.

Adolescent ; Age Factors ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Male ; Mycoplasma pneumoniae ; isolation & purification ; Pneumonia, Mycoplasma ; epidemiology ; microbiology ; Prevalence ; Respiratory Tract Infections ; epidemiology ; microbiology ; Retrospective Studies ; Seasons

OBJECTIVETo compare the detection rates of Mycoplasma pneumoniae (MP) from nasopharyngeal aspirates (NPA) and bronchoalveolar lavage fluid (BALF) in children with pneumonia.

METHODSA total of 164 hospitalized children with pneumonia were enrolled. NPA and BALF of these children were collected within 24 hours of admission, and MP-DNA was detected by fluorescence quantitative PCR. Venous blood samples of all these children were collected within 24 hours of admission and on days 7-10 of treatment, and serum MP-IgM was detected using ELISA.

RESULTSThe positive rate of MP-DNA in NAP of the 164 cases was 51.8% , which was lower than 63.4% as the detection rate of MP-IgM in serum (P=0.044), and the two detection rates were moderately consistent with each other (Kappa=0.618, P<0.01). The positive rate of MP in BALF was 71.3%, which was not significantly different with that of MP-IgM in serum (P>0.05), and the detection rates were well consistent (Kappa=0.793, P<0.01). The detection rate of MP in NPA was lower than that in BALF (P<0.01), with moderate consistency between two of them (Kappa=0.529, P<0.01). The median MP copy number in BALF was significantly higher than that in NPA (P<0.01). The MP detection rates in NPA and BALF were significantly different among different courses of disease (P<0.05). As the course of disease extended, the MP detection rates in both NPA and BALF showed a declining trend; children with MP pneumonia of 1-2 weeks' duration and 2-4 weeks' duration had a higher MP-DNA detection rate in BALF than in NPA (P<0.05).

CONCLUSIONSMP-DNA in BALF has a high sensitivity, with a great significance for early diagnosis of MP pneumonia, while NPA MP-DNA tests may lead to a missed diagnosis.

Adolescent ; Bronchoalveolar Lavage Fluid ; microbiology ; Child ; Child, Preschool ; DNA, Bacterial ; analysis ; Female ; Humans ; Infant ; Male ; Nasopharynx ; microbiology ; Pneumonia, Mycoplasma ; diagnosis

The present paper was aimed to study the relationship between the pneumonia clinical features and the pathogens of pneumonia in children by making use of association rules based on the clinical data of 6 300 cases of pneumonia. Through software analysis, the different association relationship can be obtained between different clinical features of pneumonia in children, such as gender, age and region, etc., and the pathogens of pneumonia. For example, children of different sex with the same pathogen showed different association relationships. Due to the different association relationships between the pneumonia clinical features and the pathogens of pneumonia in children of Guangzhou area, different methods in prevention and treatment of children's pneumonia should be adopted according to actual condition, in order to achieve the best results.
Adolescent ; Age Factors ; Bronchopneumonia ; epidemiology ; microbiology ; Child ; Child, Preschool ; China ; epidemiology ; Female ; Humans ; Incidence ; Infant ; Male ; Pneumonia ; epidemiology ; microbiology ; Pneumonia, Mycoplasma ; epidemiology ; microbiology ; Pneumonia, Viral ; epidemiology ; microbiology ; Sex Factors ; Software

Amino Acid Sequence ; Animals ; Bacterial Proteins ; genetics ; metabolism ; Bacterial Toxins ; genetics ; metabolism ; Base Sequence ; Community-Acquired Infections ; microbiology ; Gene Expression Regulation, Bacterial ; Humans ; Lung ; microbiology ; pathology ; Mycoplasma pneumoniae ; Pneumonia, Mycoplasma ; microbiology ; Respiratory Distress Syndrome, Adult ; microbiology

OBJECTIVETo investigate the infection rate and genotypes of Mycoplasma pneumoniae (MP) by examining bronchoalveolar lavage fluid from children with community acquired pneumonia (CAP).

METHODSPolymerase chain reaction (PCR) was used for detecting MP in bronchoalveolar lavage fluid from 220 children hospitalized with CAP, and the accuracy was confirmed by quantitative real-time PCR. Positive samples were digested with HaeⅡ and Hae Ⅲ and compared with standard strain to analyze the genotypes of MP from positive samples. The accuracy of genotyping was confirmed by sequencing the amplified products of some randomly selected positive samples.

RESULTSThe positive rate of MP in 220 samples was 55.0% (121/220). MP infection occurred mostly in preschool and school-age children (63.5%, 101/159), and the lowest positive rate was seen in children aged under 6 months (20%, 1/5). The positive rate showed no significant differences between sexes and between seasons. Sixty randomly selected MP-positive samples showed a genotype of P1 type 1 after restriction digestion, which was further confirmed by sequencing of 4 samples.

CONCLUSIONSMP is one of the main pathogens of pneumonia in children, and the MP infection rate is significantly correlated with age. The dominant genotype of MP in children is P1 type 1.

Adolescent ; Child ; Child, Preschool ; Female ; Genotype ; Hospitalization ; Humans ; Infant ; Male ; Mycoplasma pneumoniae ; classification ; genetics ; Phylogeny ; Pneumonia, Mycoplasma ; microbiology ; Real-Time Polymerase Chain Reaction ; Seasons